Field of the Invention
The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device for reducing a color defect or a color difference which occurs in the front or side of the organic light emitting display device.
Discussion of the Related Art
Recently, as society advances to the information-oriented society, the field of display devices which visually express an electrical information signal is rapidly advancing. Various types of display devices, having excellent performance in terms of thinning, lightening, and low power consumption, have been developed.
Examples of the display devices include liquid crystal display (LCD) devices, plasma display panel (PDP) devices, field emission display (FED) devices, organic light emitting display devices, etc.
In particular, the organic light emitting display devices use self-emitting devices. In comparison with other display devices, the organic light emitting display devices have a fast response time, high emission efficiency, high luminance, and a broad viewing angle.
An organic light emitting device includes an organic emission layer which is formed between two electrodes. An electron and a positive hole are injected from the two electrodes into the organic emission layer, and an exciton is generated by combining the electron with the positive hole. The organic light emitting device is a device using the principle that light is emitted when the generated exciton is dropped from an excited state to a ground state.
Organic light emitting display devices for emitting white light can be applied to various fields such as backlights, illumination, etc. and are being recognized as important display devices.
Examples of a method where an organic light emitting display device realizes white may include a single layer emission method, a multilayer emission method, a color conversion method, an element stacked method, etc. The multilayer emission method among the methods is being used at present. In the multilayer emission method, lights are respectively emitted from a plurality of layers, and white is realized by a combination of colors.
An organic light emitting display device using the multilayer emission method includes two or more devices which have different peak wavelengths and are connected to each other. Due to two or more peak wavelengths, white light is emitted by a combination of emission areas having different peak wavelengths in a spectrum. However, since a peak wavelength of a spectrum is changed depending on a position at which an organic light emitting display device is seen, a color displayed on a screen of the organic light emitting display device is changed, and for this reason, it is difficult to realize a uniform screen of the organic light emitting display device.